Caterpillar Earnings: Added Exposure to Mining Takes a Toll

Earnings Sink 43% Amid Weaker Demand for Mine Equipment

Caterpillar Inc.'s 43% drop in second-quarter earnings, steeper than expected, shows the downside of the company's increased exposure to mining.

The Peoria, Ill., company is best known for its yellow diggers, bulldozers and other construction machines. But recent results are being driven more by a plunge in demand for mining equipment, partly offset by steady sales of giant engines used for such things as moving natural gas through...